fix(core): sanitize tool function names to satisfy Gemini constraints

[ProdByBuddha]

Summary

Prevents 400 INVALID_ARGUMENT errors by sanitizing function_declaration names in the tool schema to meet Gemini’s naming constraints:

• Must start with a letter (A-Z, a-z) or underscore (_)
• Allowed characters thereafter: letters, digits (0-9), underscore (_), dot (.), colon (:), dash (-)
• Maximum length: 64 characters
  Sanitization is applied both during discovery (prefixed tool names) and immediately prior to sending the schema to the API. Diagnostic logs are emitted when a name is altered.

Details

This change introduces:

• A NAME_RE regex and sanitizeName() helper to enforce naming rules.
• Mutation of tool names at registration/discovery time to avoid invalid names reaching the API.
• Updates to getFunctionDeclarations() and getFunctionDeclarationsFiltered() so schema names are sanitized just before submission.
• Retains original names internally for execution but exposes validated names to the model/LLM interface.
• Console logging when sanitization occurs, enabling easier detection of upstream tool-name issues.

Related Issues

Closes #12869
Closes #10663
Closes #5468
Closes #5270

• more...

How to Validate

1. Build the package:

   npm ci
   npm run build

2. Link locally (optional):

   npm link

3. Run a sample tool discovery which registers names with invalid characters (e.g., leading digits, spaces, slashes).

4. Inspect logs for entries like:

   [Gemini CLI] Sanitized invalid function name: { original: "123tool/run", sanitized: "_23tool.run" }

5. Trigger a conversation or call using the sanitized tool. The API should succeed, no longer returning a 400 INVALID_ARGUMENT error.

6. Confirm valid tool names (that already met naming rules) remain unchanged.

7. Edge cases:

   • A tool name longer than 64 characters is truncated.
   • A tool name starting with a digit or symbol gets transformed to start with an underscore.
   • Tool names containing spaces or special characters get them replaced with underscores.

Signed-off-by: Billy Coleman III thebuddhaverse@icloud.com

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[gemini-code-assist]

Summary of Changes

Hello @ProdByBuddha, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses a critical compatibility issue with the Gemini API by implementing robust sanitization for tool function names. By ensuring that all function_declaration names conform to Gemini's specific naming conventions before being sent to the API, it effectively eliminates 400 INVALID_ARGUMENT errors and improves the reliability of tool interactions. The changes introduce a dedicated sanitization utility and integrate it at key points in the tool registration and declaration retrieval process, while also providing clear diagnostic feedback when names are modified.

Highlights

• API Compatibility: Ensures function_declaration names adhere to Gemini API constraints, preventing 400 INVALID_ARGUMENT errors by sanitizing names before submission.
• Name Sanitization Logic: Introduces a sanitizeName() helper function and NAME_RE regex to enforce naming rules (start with letter/underscore, allowed characters, max 64 length).
• Dual-Phase Sanitization: Applies sanitization both during tool discovery (for prefixed names) and immediately prior to sending the schema to the Gemini API.
• Internal Name Preservation: Original tool names are retained internally for execution, while only the sanitized names are exposed to the model/LLM interface.
• Diagnostic Logging: Emits console logs when a tool name is altered due to sanitization, aiding in debugging and identifying upstream naming issues.

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[gemini-code-assist]

Code Review

This pull request introduces a sanitization mechanism for tool function names to comply with Gemini API constraints, preventing 400 INVALID_ARGUMENT errors. The approach of sanitizing names at registration and just before API submission is solid. However, I've found a critical issue in the sanitization logic itself where the regex for handling invalid starting characters is too greedy, leading to incorrect name transformations. My review includes a specific code suggestion to correct this behavior.

[ProdByBuddha]

Code Review

This pull request introduces a sanitization mechanism for tool function names to comply with Gemini API constraints, preventing 400 INVALID_ARGUMENT errors. The approach of sanitizing names at registration and just before API submission is solid. However, I've found a critical issue in the sanitization logic itself where the regex for handling invalid starting characters is too greedy, leading to incorrect name transformations. My review includes a specific code suggestion to correct this behavior.

Good eye. Committed.

[ProdByBuddha]

Bump

[ProdByBuddha]

bump